Besmirch is from be- (intensive) + smirch ('to discolor, stain'), of uncertain origin, perhaps from Old French esmorcher ('to torture, hurt'). Important recorded forms include be- (Old English) and smirch (Middle English). Morphologically, the word is a built form whose named elements carry part of the historical sense. Its deeper history remains uncertain, with proposed links left as possibilities rather than a single settled derivation. The current sense covers to soil or to damage someone's reputation or honor. The wider family includes derived forms such as besmirchment and related words such as smirch.